The invention is particularly well suited for use in an apparatus that is designed to quench individual metal plates composed of any suitable material, e.g. aluminum or steel, after the metal plates have passed from a heat treatment furnace. Such quenching apparatuses employ a plurality of rows of metal tire-like wheels or rollers which are driven, in unison, to move and support the hot metal plates as they pass along a fixed horizontal pathway through an enclosed chamber where the hot metal plates are contacted with liquid from a series of nozzles which are located above and below the pathway to direct streams of liquid against the metal plates in a downstream direction relative to the direction in which the metal plates travel. The quantity of the quenching liquid is naturally dependent upon the thickness of the metal plate being quenched.
A wake, somewhat similar to that created by a boat, is produced by the rollers as they contact the quenching liquid. These wakes circumvent and isolate tear-shaped areas of the metal plate extending from the leading edges of the rollers, first to contact the liquid, downstream behind the rollers, and prevent adequate liquid from contacting the metal plate in these areas, thereby creating non-uniform quenching of the metal plate during the initial, highly critical stage of the quenching process. Such non-uniform quenching causes the metal plate to buckle and twist making the distorted metal plate exceedingly difficult to handle and, oftentimes, unacceptable from a flatness standpoint. Moreover, the wakes interfer with the rate at which it is necessary to quench the metal plate to produce the metallurgical properties desired in the metal plate. The invention is primarily designed to overcome this problem by the provision and location of nozzles which are positioned to eliminate or substantially reduce the wakes caused by the rollers so that the metal plate when it is hottest at the beginning of the quenching process is uniformly contacted with liquid.
Briefly stated, the invention is in a quenching apparatus that comprises a horizontally elongated chamber in which a plurality of transversely oriented rows of parallel metal, tire-like wheels or rollers are located to support an element as it travels along a fixed horizontal pathway through the apparatus. A plurality of nozzles are positioned vertically above and below the pathway to impinge quenching liquid against the element. The nozzles located below the pathway adjacent the opening through which the element enters the apparatus, are positioned between adjacent rows of rollers to impinge streams of liquid to disrupt and substantially eliminate the wakes created by the rollers as large quantities of high velocity quenching liquid contact them. It can be appreciated from above that the term "element", as used herein, has reference to continuous or discrete plate-like material which has a length and width sufficient for the supporting rollers to create wakes thereagainst, as distinguished from small wire-like material.
Another aspect of the invention is in the particular location of the nozzles above the pathway adjacent the entrance opening. Such nozzles are positioned to produce overlapping patterns of liquid at least initially against the element to insure complete coverage of the element with liquid, especially the trailing end of the element which, in the past, has sometimes been alternately cooled and reheated as it passes between spaced streams of liquid from inadequately positioned nozzles.
Still another aspect of the invention is in the positioning of nozzles above the pathway adjacent the end of the apparatus from which the element exits to direct streams of liquid in a counterflow direction against liquid flowing atop the traveling element and attempting to escape or exit the apparatus with the element.
As previously indicated, large quantities of high velocity liquid are used to quench thicker metal plates providing a horrendous problem of excess liquid disposal, as this large volume of water literally attempts to escape the apparatus with the moving plates. A number of blow-off nozzles are provided to cooperate with the counterflow nozzles adjacent the exit end of the apparatus to direct streams of fluid in lateral directions against the liquid moving atop the traveling plates, to blow such liquid laterally off the opposing longitudinal marginal edges of the plates and help prevent the undesireable exodus of liquid from the apparatus.